Automatic draft controlling apparatus



Nov. 9, 1943. c. B. RIVERS AUTOMATIC DRAFT CONTROLLING APPARATUS Filed March 6, 1942 0 w .r w w a w w m z, w w 2 b @F a M m mu 1 M w w \m 2 13 3 0 l GaZv i/n b11362) are INVENTOR.

Patented Nov. 9, 1943 UNITED STATES PATENT OFFICE AUTOMATIC DRAFT CON TROLLIN G APPARATUS Calvin B. Rivers, Chesterfield, S. 0.

Application March 6, 1942, Serial No. 433,666

1 Claim.

This invention relates to automatic draft controlling apparatus for furnaces, and its general v object is to provide an apparatus which is primarily designed for use with a wood burning furnace of the heating system of a tobacco curing barn, in order to maintain a substantially uniform temperature within the barn, and such not only results in a material saving of fuel, but also properly cures the tobacco in an expeditious man ner, as well as brings about the desired color and flavor thereto.

A further object is to provide an automatic draft controlling apparatus that is simple in construction, inexpensive to manufacture, easy to install, and is extremely efficient in operation, use and service.

This invention also consists in certain other features of construction and in the combination and arrangement of the several parts, to be hereinafter fully described, illustrated in the accompanying drawing and specifically pointed out in the appended claim.

In describing the invention in detail, reference will be had to the accompanying drawing wherein like characters denote like or corresponding parts throughout the several views, and in which:

Figure l is a vertical sectional View taken through a tobacco barn and illustrates the manner in which my apparatus is installed relative to the furnace of the heating system and the barn.

Figure 2 is a top plan view of Figure 1.

Figure 3 is an enlarged side view of the apparatus with parts broken away and in section.

Figure 4 is a front view of the thermostat device of the apparatus.

Referring to the drawing in detail, the letter A indicates a tobacco curing barn having the usual tier poles B secured therein and from which the tobacco is suspended, as will be apparent. A furnace C is mounted to project through the front wall of the barn, with its front or fuel receiving end exteriorly of the barn, and extending from the rear end of the furnace is a flue pipe D that is connected at its rear end to a junction box E, from which extends branch pipes F.

My controlling apparatus includes a draft or cold air conduit having a vertical intermediate section I connected to a side of the exterior projecting portion of the furnace, adjacent to the lower end thereof, and through the medium of a horizontal section 2. Secured to and rising from the section I is an upper casing like damper section 3 having a reduced lower end portion formed with an annular flange that is mounted in the intermediate section, as best shown in Figure 3, for detachable association therewith. The upper section from its reduced lower portion is shown as being square in cross section and the upper end thereof is closed by a top wall 4' that projects forwardly of the front wall, the latter having an inlet opening at its upper end for passage of air within the conduit and thence to the furnace for disposal below the firebox, to bring about combustion as will be apparent.

Journaled in and bridging the side walls of the upper section at the front thereof and of course below the inlet opening, is a damper shaft 5 that has one end extending through a side wall and fixed to the interior portion of the shaft is a damper plate 6 for controlling the passage of air through the conduit. Fixed to the extending end of the shaft is a substantially semidisk shaped member 7 having a row of apertures 8 along the curved edge thereof, and any one of certain of the apertures is adapted to receive one end of a coil spring 9, for urging the damper to open position. By the provision of the plurality of apertures, it will be seen that the coil spring is adjustable relative to the member I. The opposite end of the spring is connected to an arm l0 fixed to and rising from the outer end of the furnace, as shown in Figure 2.

The damper is urged and moved to closed position against the action of the spring, by a thermostat l2 of the wafer type in the form shown, and the thermostat which of course is arranged within the barn to be acted upon by the temperature therein, i secured by an adjusting screw 16 to the lower end of 3. depending bar l3 which is fixed at the upper end to a tier pole B. A depending bar 20 has its upper end pivotally connected to the tier pole B by a hinge 14 that is fixed to the rear face of the pole. The bar 20 contacts with the wafer and is swung on its hinge when the Wafer expands.

A stiff wire or rod I! that has one end secured to the lower end of the hinged bar 20 and itsopposite end is connected to the semidisk shaped member I, the latter end being bent at right angle to the length of the rod, and is mounted and secured in any one of the apertures 8, below the connection of the spring with the member 1,,

bracket l5 secured at the upper end to the tier pole B, as shown in Figures 3 and 4. The other end of the tube projects through the wall of the barn A near the member 1.

While it has been stated that the thermostat is fixedto the bar l3, it may only bear against the bar. In that event the adjusting screw will be secured to the thermostat, to support the same betweenthe bar and the bracket, and the screw will be preferably swiveled to the thermostat.

From the above description and disclosure in the drawing, it will be obvious that my apparatus automatically controls the natural'draft to the furnace, in accordance with the temperature in the barn, that is the expansion and contraction of the thermostat will result in operating the damper, through the medium of the rod I1 and What I claim is:

An automatic draft controlling apparatus for the furnace of a heating system of a tobacco barn having the usual tier poles therein, and said apparatus comprising a cold air conduit connected to the furnace and disposed exteriorly of the barn, a damper in said conduit, a coil spring connected \to the damper for urging the latter to open position, a bar having onev end pivotally connected to a tier pole and dependingv therefrom,

a wafer type thermostat fixed to the bar adja- ,cent the lower end thereof, a. substantiallyV- shaped bracket secured to and depending from said tier pole and having its apex end spaced from and in confronting relation with the thermostat. a fixed bar depending from the pole between the diverging legs of and in the plane of the bracket, an adjusting screw secured to the fixed bar and bearing against the thermostat, a rod having one.

end connected to the lower end of the pivotally connected bar and itsopposite end to the damper for moving thelatter against the action of the 1 spring, and a tube mounted horizontally ln'the barn and projecting through thefront wall having the said rod trained therethrough.

CALVIN B. RIVERS. 

